The indications and outcome of paediatric corneal
transplantation in New Zealand: 1991–2003H Y Patel, S Ormonde, N H Brookes, L S Moffatt, C N J McGhee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Br J Ophthalmol 2005;89:404–408. doi: 10.1136/bjo.2004.053116
NZNEB since 1991 has been the maintenance of a compre-
Aim: To evaluate patient characteristics, indications, surgical
hensive database, supported by New Zealand ophthalmic
details, and outcome of paediatric keratoplasty in New
surgeons, in which prospective data are collected on all
aspects of corneal donation and transplantation. In this
Methods: As part of a prospective longitudinal study,
study the NZNEB database was analysed for the 13 year
paediatric keratoplasty data collected by the New Zealand
period 1991 to 2003 with respect to patient characteristics,
National Eye Bank (NZNEB) was analysed for the 13 year
indications, surgical details, and outcome of paediatric
Results: During the study period the NZNEB supplied 2547corneas for keratoplasty, of which 65 (3%) were used for
paediatric patients (14 years or younger). The 65 kerato-
As part of a longitudinal, prospective study, the electronic
plasties were performed in 58 eyes of 52 patients (66% male,
records of the NZNEB were analysed for the 13 year period
34% female, mean age 10.6 years, SD 4.3 years).
1991–2003 with respect to demographics of recipients,
Indications were classified into three groups: congenital
indications, donor information, surgical details, and outcome
(16%, n = 9), acquired non-traumatic (74%, n = 43), and
acquired traumatic (10%, n = 6). Peters’ anomaly (7% of
Data are entered into the computerised NZNEB database in
total), keratoconus (67%), and penetrating trauma (8%) were
a prospective manner by eye bank staff. Donor information is
the most common indications in each group, respectively.
entered at the time of donor tissue procurement. Recipient
82% of keratoplasties with known outcome survived (clear
and surgical information is collected from surgeons at the
graft) 1 year postoperatively, 16% failed, and one patient
time of operation. Follow up data are obtained at 1 and
died. Keratoplasty for congenital indications had a lower
2 years postoperatively and are collected from surgeons by
1 year survival rate (78%) compared to acquired non-
way of a mailed questionnaire sent out at the appropriate
traumatic (85%) and traumatic (100%) indications, although
Statistical analysis was performed in consultation with a
the difference was not statistically significant (p = 0.65). 38%
medical statistician from the epidemiology department of the
of patients with known outcome had a 1 year postoperative
University of Auckland. The SPSS V 12 software package was
best corrected Snellen visual acuity (BCSVA) of 6/9 or better,
used. Statistical methods were the Fisher’s exact test (when
and 60% had a BCSVA of 6/18 or better. Visual outcome
total number of observations were less than 20) and x2
was significantly better for acquired compared to congenital
testing to compare proportions between groups, the Student’s
t test to compare means between groups, and logistic
Conclusion: Analysis of the NZNEB database provided
regression modelling to identify factors associated with
valuable information in relation to paediatric keratoplasty
decreased keratoplasty survival. The level of statistical
in New Zealand. In particular, this study highlighted an
significance was p,0.05 unless stated otherwise. Visual
unusually high prevalence of keratoconus as an indication for
acuity was converted to a logMAR scale for the purposes of
keratoplasty. In addition, a high 1 year survival rate and
good visual outcome were identified, especially in cases ofkeratoplasty for acquired conditions.
RESULTSPatient demographicsDuring the 13 year study period the NZNEB supplied 2547corneas for keratoplasty, of which 65 (3%) were used for
Paediatric keratoplasty is a difficult undertaking which patients within the paediatric age group (14years or
presents a wide range of challenges preoperatively,
younger). The 65 keratoplasties were performed in 58 eyes
intraoperatively, and postoperatively.1–6 The presence of
of 52 patients. The mean age of patients at the time of
amblyopia, associated ocular pathology, and greater severity
operation was 10.6 (SD 4.3) years, median age 12.0 years,
of disease may significantly limit visual outcome.1–6 The
and range 2 weeks to 14.0 years. The sex distribution was
surgical procedure is technically more complex owing to the
66% (n = 34) male and 34% (n = 18) female.
decreased rigidity and increased elasticity of the infantcornea and sclera, the smaller size of the infant eye, the
increased intraoperative fibrin formation and the positive
The indications for paediatric keratoplasty are presented in
vitreous pressure.1–6 Postoperative follow up and manage-
table 1. The diagnostic classification system developed by
ment may be more complicated, and graft rejection is often
Stulting et al1 was used to facilitate comparison with other
The New Zealand National Eye Bank (NZNEB), founded in
Abbreviations: BCSVA, best corrected Snellen visual acuity; CHED,
1991, is the major supplier of donated ocular tissue for
congenital hereditary endothelial dystrophy; ECD, endothelial cell
transplantation in New Zealand. A standard protocol of the
density; NZNEB, New Zealand National Eye Bank
Paediatric corneal transplantation in New Zealand
Table 1 Indications for paediatric keratoplasty
Congenital corneal opacity not otherwise specified
CHED, congenital hereditary endothelial dystrophy.
Table 2 Age and sex distribution for each diagnostic group
published reports. Indications were classified into three
indication in the less than 5 years age group and keratoconus
groups: congenital, acquired non-traumatic, and acquired
traumatic conditions. The congenital group accounted for16% (n = 9) of keratoplasties, the acquired non-traumatic
group 74% (n = 43), and the acquired traumatic group 10%
Keratoplasty was performed by 22 different surgeons in 10
(n = 6). Peters’ anomaly (7% of total, n = 4) was the most
centres throughout New Zealand. Penetrating keratoplasty
common indication in the congenital group, keratoconus
was performed in 62 cases and lamellar keratoplasty in the
(67% of total, n = 39) in the acquired non-traumatic group,
remaining three cases. The indications for lamellar kerato-
and penetrating trauma (9% of total, n = 5) in the acquired
plasty were limbal dermoid, Peters’ anomaly, and congenital
traumatic group. There were seven regraft procedures
corneal opacification not otherwise specified. Donor informa-
performed during the study period with original indications
tion was available for all corneal tissue used with mean donor
being keratoconus (n = 3), viral keratitis (n = 1), Peters’
age 44.4 (SD 18.0) years, median age 46.5 years, and range
anomaly (n = 2), and penetrating trauma (n = 1). Kerato-
10–77 years. Mean endothelial cell density (ECD) was
plasty was performed to improve visual acuity in 86%
3074 cells/mm2 (SD 386 cells/mm2), median 3065 cells/mm2,
(n = 56) of cases, for tectonic reasons in 6% (n = 4), and
and range 2578–4210 cells/mm2. The donor cornea button
for a combination of reasons in 8% (n = 5).
was sutured to the recipient corneal rim with 10-0 Nylon
The age and sex distribution for each diagnostic group are
in 95% (n = 62) and a combination of Nylon and Prolene
presented in table 2. There was no significant association
in 5% (n = 3). An interrupted suture technique was used in
between preoperative diagnosis and sex identified (congeni-
40% (n = 26), a single continuous suture in 26% (n = 17),
tal, p = 0.16; acquired non-traumatic, p = 0.26; acquired
and a combined interrupted/continuous technique in 34%
traumatic, p = 0.43; regraft, p = 0.41, x2 test). The indications
for different age groups (using stratified 5 year intervals) are
Reported preoperative ocular conditions included corneal
presented in table 3. Peters’ anomaly was the leading
vascularisation in 19% (n = 12), previous intraocular surgery
Table 3 Indications for keratoplasty for different age groups
CHED, congenital hereditary endothelial dystrophy.
less than 5 years, 82%; 5–9 years, 78%; and 10–14 years, 83%.
Table 4 Outcome of keratoplasty 1 year postoperatively
The differences between diagnostic groups (p = 0.65) and age
groups (p = 0.51) were not statistically significant. There wasno statistical difference in survival rate based on suture
method (p = 0.50) or type of postoperative medication used
The most common reason for keratoplasty failure was
irreversible rejection (10% of total, n = 5), followed by
presumed primary tissue failure (defined as failure of the
graft to clear) (4%, n = 2) and trauma (2%, n = 1). Episodes
of reversible rejection were reported in 22% (n = 9) of casesthat survived 1 year postoperatively. Logistic regressionanalysis was performed in an attempt to identify factorswhich may be associated with decreased keratoplastysurvival. Factors included were pre-existing corneal vascular-
in 14% (n = 9), a history of elevated intraocular pressure in
isation, preoperative glaucoma, active inflammation at
6% (n = 4), and active ocular inflammation at the time of
keratoplasty, small or large graft size, additional intraopera-
operation in 9% (n = 6). Additional operative procedures
tive procedures, immediate postoperative complications, and
performed were anterior vitrectomy in 5% (n = 3), cataract
episodes of reversible rejection. However, no individual factor
extraction and intraocular lens insertion in 3% (n = 2),
was identified from this analysis which resulted in a
iridectomy in 2% (n = 1), and iridectomy plus synechiolysis
statistically significant decrease in keratoplasty survival.
in 2% (n = 1). No significant intraoperative complications
Best corrected Snellen visual acuity (BCSVA) was reported
were reported. Early postoperative complications (within
in 90% (n = 38) of cases that survived 1 year postoperatively
3 weeks) included wound leak in 5% (n = 3), wound
(table 4). Of all paediatric keratoplasties, 38% (n = 18)
infection in 2% (n = 1), corneal ulcer in 3% (n = 2), and
achieved a BCSVA of 6/9 (20/30) or better and 60%
early graft rejection in 2% (n = 1). Postoperative medical
(n = 30) had a BCSVA of 6/18 (20/60) or better. Spectacles
management consisted of Maxitrol (dexamethasone 0.1%,
(n = 14) or contact lens (n = 2) were provided in 38% of
neomycin 0.35%) in 60% (n = 39), prednisone acetate 1%
cases. Visual outcome for each diagnostic group is presented
plus chloramphenicol 0.5% in 32% (n = 21), with other
in table 5. Visual outcome was significantly better for
antibiotic-steroid combinations in 8% (n = 5).
acquired (mean logMAR 0.2, 6/10) compared to congenitalindications (mean logMAR 1.1, 6/75) (p = 0.03). Unfor-
tunately preoperative visual acuity was not available for
Outcome was evaluated 1 year postoperatively with follow up
analysis as this was not recorded in the NZNEB database.
data available for keratoplasties performed from 1991 to2001. There were 58 keratoplasties during this interval withfollow up data available for 88% (n = 51). The remaining 12%
(n = 7) were lost to follow up. The survival rate was
New Zealand is a multicultural society with a population of
determined by analysing the percentage of keratoplasties
approximately four million, served by 110 ophthalmologists,
that were surviving (clear graft) at 1 year postoperatively.
distributed over a geographical area slightly greater than the
Eighty two per cent (n = 42) of keratoplasties survived, 16%
United Kingdom. Over 200 keratoplasties are performed
(n = 8) failed, and one patient died. Survival rates for
annually in New Zealand and the NZNEB was established in
different diagnostic groups were: congenital, 78%; acquired
1991 to support this demand. Over the 13 year study period it
non-traumatic, 85%; acquired traumatic, 100%; and regraft
was estimated that the NZNEB supplied at least 90% of all
procedures, 80%. Survival rates for different age groups were:
donated ocular tissue. Therefore, analysis of the NZNEB
Table 5 Keratoplasty outcome for each diagnostic group and for regraft procedures
Table 6 Indications for paediatric keratoplasty reported in the literature
Paediatric corneal transplantation in New Zealand
Table 7 Summary of published survival rates in paediatric keratoplasty
database provides an accurate representation of corneal
indications.1–4 12 13 The overall survival rate of 82% in this
disease and keratoplasty in New Zealand.
The indications for paediatric keratoplasty vary signifi-
reports.1–4 12 13 This may be because of the longer follow up
cantly in the literature. Table 6 provides a comparison
period at which survival rates were reported in some of the
between this study and the major studies published over
other studies.3 4 12 13 Another contributing factor may be the
the past two decades. Most studies used the age criteria of
high proportion of keratoplasties performed for acquired
14 years or younger. The proportion of keratoplasties
non-traumatic indications. In concurrence with other pub-
performed for congenital indications ranged from 14–64%,
lished reports, a higher survival rate for acquired compared to
for acquired non-traumatic 19–80%, and for acquired
congenital indications was identified in this study,1–4 12 13
traumatic 6–29%.1–4 7 In this study, the proportion of
although this did not reach statistical significance, possibly
keratoplasties performed for acquired non-traumatic indica-
owing to the small size of the congenital group. Of particular
tions (74%) was significantly greater than that for congenital
note, keratoplasty performed for keratoconus had an
(16%) and acquired traumatic (10%) indications. This is in
excellent prognosis with a 1 year survival rate of 90%.
contrast with the majority of published reports, in which
In other published reports, several factors have been
congenital indications contribute a significantly greater
identified which increase the risk of failure in paediatric
keratoplasty.1–4 14–19 Performance of an additional surgical
Keratoconus was the most common acquired non-trau-
procedure at the time of keratoplasty was most significantly
matic indication in this study, accounting for 67% of all
associated with a decreased survival rate, with other factors
keratoplasties. This was notably higher than other published
reported including preoperative glaucoma, associated ocular
reports where keratoconus accounted for only 0–11% of
conditions, and corneal vascularisation.1–4 14–19 In this study,
paediatric keratoplasties, with post-infectious corneal scar-
no factor was independently associated with a statistically
ring the most common acquired non-traumatic indication
significant increase in failure rate. However, the relatively
reported in the literature.1–4 7 Similar to previous studies,1–4 7
small number of subjects limited this analysis. The influence
the most common congenital indication identified in this
of age alone on paediatric keratoplasty survival has been
study was Peters’ anomaly followed by congenital hereditary
evaluated with conflicting reports in the literature. Aasuri et
endothelial dystrophy, and the most common indication in
al4 identified a correlation between age under 5 years and
the acquired traumatic diagnostic group was penetrating
allograft rejection, and commented that this may be because
of a more active immune system in younger patients. Other
The notably high prevalence of keratoconus as an indica-
studies, including this one, did not identify such an
tion for paediatric keratoplasty reflects that which was
identified by Edwards et al,8 who reported that keratoconus
Poor visual outcome in a surviving keratoplasty (clear
was the leading indication (45%) for keratoplasty in the adult
graft) is well recognised within the paediatric age group and
population in New Zealand, accounting for a significantlyhigher proportion of keratoplasties compared to other
is most commonly a result of amblyopia, non-corneal ocular
published reports. Ethnic differences in keratoconus pre-
abnormalities, and postoperative astigmatism.1–4 17–19 In con-
valence, severity, and rate of disease progression have been
cordance with other published reports, this study identified a
well recognised,9–11 and keratoconus is thought to be
poorer visual outcome for congenital compared to acquired
particularly prevalent in Maori and Pacific Island commu-
indications.1–4 17–19 A higher prevalence of amblyopia and
nities, which constitute a large proportion of the New
associated ocular abnormalities in the congenital group has
Zealand population. Edwards et al8 postulated that this high
been cited as the reason for the less successful visual outcome
prevalence, and possibly more rapid disease progression and
in this group.1–4 17–19 We suspect that this may also be the case
severity, has led to the uniquely high prevalence of
in this study. Important considerations therefore are the
keratoconus as an indication for keratoplasty in New
timing of keratoplasty which should not be delayed
Zealand. Similarly, this may explain the high prevalence of
unnecessarily and the high priority of postoperative amblyo-
keratoconus identified in this study. Over the past 4 years the
NZNEB database has incorporated recipient ethnicity data to
Analysis of the New Zealand National Eye Bank database
further investigate the relation between ethnicity and
has provided valuable information in relation to paediatric
keratoplasty in New Zealand. In particular, this study
Survival rates published by the foremost studies of
identified an unusually high prevalence of keratoconus as
paediatric keratoplasty are presented in table 7. Mean follow
an indication for paediatric keratoplasty in New Zealand.
up generally ranged from 1–2 years and the reported survival
High success rates at 1 year postoperatively, in terms of both
rates ranged from 46–80%.1–4 12 13 Keratoplasty performed
keratoplasty survival and visual outcome were identified,
for congenital indications had a lower survival rate com-
especially in cases of keratoplasty for acquired corneal
pared to acquired non-traumatic and acquired traumatic
3 Cowden JW. Penetrating keratoplasty in infants and children. Ophthalmology
The authors acknowledge the fundamental contribution to this
4 Aasuri MK, Prashant G, Gokhle N, et al. Penetrating keratoplasty in children.
research by Associate Professor Gillian Clover, PhD, FRACO, founder
and first scientific director of the NZNEB; the key role of Dr David
5 Stulting RD. Penetrating keratoplasty in children. In: Brightbill FS, ed.
Pendergrast, clinical director; the chairman and trustees of the eye
Corneal surgery: theory, technique and tissue, 3rd ed. St Louis: Mosby,
bank for continued support, and past and present managers,
6 Vajpayee RB, Ramu M, Panda A, et al. Oversized grafts in children.
transplant coordinators, and scientific staff who have contributed
to clinical and scientific aspects of the NZNEB over the past 13 years.
7 Dada T, Sharma N, Vajpayee RB. Indications for pediatric keratoplasty in
Finally, the authors thank the ophthalmologists of New Zealand for
their support and participation in the research and clinical activities
8 Edwards M, Clover GM, Brookes N, et al. Indications for corneal
transplantation in New Zealand: 1991–1999. Cornea 2002;21:152–5.
9 Pearson A, Soneji B, Sarvananthan N, et al. Does ethnic origin influence the
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H Y Patel, S Ormonde, C N J McGhee, Department of Ophthalmology,
11 Tuft SJ, Moodaley LC, Gregory WM, et al. Prognostic factors for the
Faculty of Medical and Health Sciences, University of Auckland,
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12 Legeais JM, Jobin D, Pouliquen Y. Keratoplasties chez l’enfant. J Fr Ophtalmol
N H Brookes, L S Moffatt, C N J McGhee, New Zealand National Eye
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14 Parmley VC, Stonecipher KG, Rowsey JJ, et al. Peters’ anomaly: a review of
Correspondence to: Professor Charles N J McGhee, Department of
26 keratoplasties in infants. Ophthalmic Surg 1993;24:31–5.
Ophthalmology, Private Bag 92019, University of Auckland, Auckland,
15 Williams KA, Roder D, Esterman A, et al. Factors predictive of corneal graft
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17 Waring GO III, Laibson PR. Keratoplasty in infants and children. Trans Am
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2 Dana MR, Moyes AL, Gomes JAP, et al. The indications for and outcome in
influences on corneal graft survival in 539 transplants. Acta Ophthalmol
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Title: Counterstrain manipulation in the treatment of Restless Legs Syndrome: a pilot single-blind randomised controlled trial; the CARL Trial. Peters, T 1, MacDonald, R* 1, Leach, CMJ 2 1 London College of Osteopathic Medicine, Marylebone, London, UK 2 Clinical Research Centre for Health Professions, University of Brighton, UK. CORRESPONDENCE : R S MacDonald, LCOM, 8, Boston Place, NW1
BRITISH PHARMACOPOEIA CHEMICAL REFERENCE SUBSTANCE MATERIAL SAFETY DATA SHEET The substance to which this Safety Data Sheet relates is supplied exclusively as a British Pharmacopoeia Chemical Reference Substance (BPCRS) for chemical test and assay purposes. It is not intended to be used for any other purpose and is not for human consumption . The BPCRS is supplied in accordance